1. Field of the Invention
The field of the invention is the petrochemical industry, and more particularly, the cleaning of fin tubes in air coolers.
2. Description of Related Art
The term “air cooler” as used herein refers to certain apparatus in common use in the petrochemical industry. Two air coolers 10 are shown in a typical installation in FIG. 1 wherein two air cooler bays are shown. FIG. 2 is an end view of another typical air cooler bay 24. In a typical usage, overhead vapor from a refinery distillation tower is piped through inlets 12 into an inlet header 14. The inlet header is in communication with the inlet ends (first ends) of numerous fin tubes 16, and the vapor moves through the fin tubes and out the outlet ends (second ends) of the fin tubes into a return (or outlet) header 18 for subsequent discharge through outlets 20 back into the refinery system. The inlet and outlet headers are part of the air cooler frame 22 that holds the fin tubes.
The crosses in FIG. 2 represent the centers of a typical arrangement of the fin tubes, which are in rows and equally spaced. The crosses also represent the centers of holes in the inlet header and outlet header that are in direct alignment with each of the fin tubes. In normal use these holes are closed by bull plugs. The fin tubes are typically spaced on approximately 2⅜ inch centers and typically have one-half inch inside diameters. Each fin tube has exterior fins about their outside circumference, the fins being spaced by approximately one-sixteenth inch.
In a typical operation the vapors from the distillation tower are cooled, while in the fin tubes, by blowing air across the fin tubes using fans. As the vapors cool, it is common for carbonate scale and other materials to be deposited in the fin tube interiors.
The air cooler fin tubes 16 are typically cleaned by a cleaning tool having a fluid discharge end that is insertable through an open inlet header hole into the aligned fin tube inlet end. A typical cleaning tool is a line mole having a flexible hose with a discharge tip. Cleaning fluid is pumped into the hose at high pressure and is discharged through the discharge tip and against the adjacent interior wall of the fin tube being cleaned. The discharged cleaning fluid and dislodged material, e.g. carbonate scale buildup, exits the fin tube at the fin tube second end, and the majority of such cleaning fluid and dislodged material continue through the aligned hole in the air cooler outlet header.
A significant operational, safety and regulatory concern related to this cleaning process is the cleaning fluid and dislodged material being discharged on to the surrounding equipment or the ground. Operators have attempted to isolate the area subject to splashing and exiting fluids and dislodged materials, by temporarily isolating and/or covering the area using sheets of plywood, etc. All current methods of controlling the splashing and exiting fluids and dislodged materials are labor and material intensive, making the process time consuming and expensive.
Equipment is needed that will install quickly and capture the splashing and exiting cleaning fluids and dislodged materials while the air cooler fin tubes are being cleaned.